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Zhou Z, Feng S, Hua Z, Li Z, Chen Y, Zhao D. Dissociation dynamics of carbon dioxide cation (CO 2 +) in the C 2Σ g + state via [1+1] two-photon excitation. J Chem Phys 2020; 152:134304. [PMID: 32268747 DOI: 10.1063/1.5143848] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The dissociation dynamics of CO2 + in the C2Σg + state has been studied in the 8.14-8.68 eV region by [1+1] two-photon excitation via vibronically selected intermediate A2Πu and B2Σu + states using a cryogenic ion trap velocity map imaging spectrometer. The cryogenic ion trap produces an internally cold mass selected ion sample of CO2 +. Total translational energy release (TER) and two-dimensional recoiling velocity distributions of fragmented CO+ ions are measured by time-sliced velocity map imaging. High resolution TER spectra allow us to identify and assign three dissociation channels of CO2 + (C2Σg +) in the studied energy region: (1) production of CO+(X2Σ+) + O(3P) by predissociation via spin-orbit coupling with the repulsive 14Πu state; (2) production of CO+(X2Σ+) + O(1D) by predissociation via bending and/or anti-symmetric stretching mediated conical intersection crossing with A2Πu or B2Σu +, where the C2Σg +/A2Πu crossing is considered to be more likely; (3) direct dissociation to CO+(A2Π) + O(3P) on the C2Σg + state surface, which exhibits a competitive intensity above its dissociation limit (8.20 eV). For the first dissociation channel, the fragmented CO+(X2Σ+) ions are found to have widely spread populations of both rotational and vibrational levels, indicating that bending of the parent CO2 + over a broad range is involved upon dissociation, while for the latter two channels, the produced CO+(X2Σ+) and CO+(A2Π) ions have relatively narrow rotational populations. The anisotropy parameters β are also measured for all three channels and are found to be nearly independent of the vibronically selected intermediate states, likely due to complicated intramolecular interactions in the studied energy region.
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Affiliation(s)
- Zhengfang Zhou
- Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Shaowen Feng
- Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Zefeng Hua
- Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Zhen Li
- Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Yang Chen
- Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Dongfeng Zhao
- Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
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Zhou J, Luo Z, Yang J, Chang Y, Zhang Z, Yu Y, Li Q, Cheng G, Chen Z, He Z, Che L, Yu S, Wu G, Yuan K, Yang X. State-to-state photodissociation dynamics of CO 2 around 108 nm: the O( 1S) atom channel. Phys Chem Chem Phys 2020; 22:6260-6265. [PMID: 32129384 DOI: 10.1039/c9cp06919d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
State-to-state photodissociation of carbon dioxide (CO2) via the 3p1Πu Rydberg state was investigated by the time-sliced velocity map ion imaging technique (TSVMI) using a tunable vacuum ultraviolet free electron laser (VUV FEL) source. Raw images of the O(1S) products resulting from the O(1S) + CO(X1Σ+) channel were acquired at the photolysis wavelengths between 107.37 and 108.84 nm. From the vibrational resolved O(1S) images, the product total kinetic energy releases and the vibrational state distributions of the CO(X1Σ+) co-products were obtained, respectively. It is found that vibrationally excited CO co-products populate at as high as v = 6 or 7 while peaking at v = 1 and v = 4, and most of the individual vibrational peaks present a bimodal rotational structure. Furthermore, the angular distributions at all studied photolysis wavelengths have also been determined. The associated vibrational-state specific anisotropy parameters (β) exhibit a photolysis wavelength-dependent feature, in which the β-values observed at 108.01 nm and 108.27 nm are more positive than those at 107.37 nm and 107.52 nm, while the β-values have almost isotropic behaviour at 108.84 nm. These experimental results indicate that the initially prepared CO2 molecules around 108 nm should decay to the 41A' state via non-adiabatic coupling, and dissociate in the 41A' state to produce O(1S) + CO(X1Σ+) products with different dissociation time scales.
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Affiliation(s)
- Jiami Zhou
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou, Zhejiang 311231, China. and State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
| | - Zijie Luo
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China. and Department of Physics, School of Science, Dalian Maritime University, 1 Linghai Road, Dalian, Liaoning 116026, P. R. China
| | - Jiayue Yang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
| | - Yao Chang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
| | - Zhiguo Zhang
- Key Laboratory of Functional Materials and Devices for Informatics of Anhui Higher Education Institutions and School of Physics and Electronic Engineering, Fuyang Normal University, Fuyang, Anhui 236041, China.
| | - Yong Yu
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
| | - Qinming Li
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
| | - Gongkui Cheng
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
| | - Zhichao Chen
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
| | - Zhigang He
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
| | - Li Che
- Department of Physics, School of Science, Dalian Maritime University, 1 Linghai Road, Dalian, Liaoning 116026, P. R. China
| | - Shengrui Yu
- Hangzhou Institute of Advanced Studies, Zhejiang Normal University, 1108 Gengwen Road, Hangzhou, Zhejiang 311231, China.
| | - Guorong Wu
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
| | - Kaijun Yuan
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
| | - Xueming Yang
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
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Hua Z, Feng S, Zhou Z, Liang H, Chen Y, Zhao D. A cryogenic cylindrical ion trap velocity map imaging spectrometer. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:013101. [PMID: 30709209 DOI: 10.1063/1.5079264] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 12/15/2018] [Indexed: 06/09/2023]
Abstract
A cryogenic cylindrical ion trap velocity map imaging spectrometer has been developed to study photodissociation spectroscopy and dynamics of gaseous molecular ions and ionic complexes. A cylindrical ion trap made of oxygen-free copper is cryogenically cooled down to ∼7 K by using a closed cycle helium refrigerator and is coupled to a velocity map imaging (VMI) spectrometer. The cold trap is used to cool down the internal temperature of mass selected ions and to reduce the velocity spread of ions after extraction from the trap. For CO2 + ions, a rotational temperature of ∼12 K is estimated from the recorded [1 + 1] two-photon dissociation spectrum, and populations in spin-orbit excited X2Πg,1/2 and vibrationally excited states of CO2 + are found to be non-detectable, indicating an efficient internal cooling of the trapped ions. Based on the time-of-flight peak profile and the image of N3 +, the velocity spread of the ions extracted from the trap, both radially and axially, is interpreted as approximately ±25 m/s. An experimental image of fragmented Ar+ from 307 nm photodissociation of Ar2 + shows that, benefitting from the well-confined velocity spread of the cold Ar2 + ions, a VMI resolution of Δv/v ∼ 2.2% has been obtained. The current instrument resolution is mainly limited by the residual radial speed spread of the parent ions after extraction from the trap.
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Affiliation(s)
- Zefeng Hua
- CAS Center for Excellence in Quantum Information and Quantum Physics, Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Shaowen Feng
- CAS Center for Excellence in Quantum Information and Quantum Physics, Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Zhengfang Zhou
- CAS Center for Excellence in Quantum Information and Quantum Physics, Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Hao Liang
- CAS Center for Excellence in Quantum Information and Quantum Physics, Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Yang Chen
- CAS Center for Excellence in Quantum Information and Quantum Physics, Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | - Dongfeng Zhao
- CAS Center for Excellence in Quantum Information and Quantum Physics, Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
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Lu Z, Chang YC, Yin QZ, Ng CY, Jackson WM. Photochemistry. Evidence for direct molecular oxygen production in CO₂ photodissociation. Science 2014; 346:61-4. [PMID: 25278605 DOI: 10.1126/science.1257156] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Photodissociation of carbon dioxide (CO2) has long been assumed to proceed exclusively to carbon monoxide (CO) and oxygen atom (O) primary products. However, recent theoretical calculations suggested that an exit channel to produce C + O2 should also be energetically accessible. Here we report the direct experimental evidence for the C + O2 channel in CO2 photodissociation near the energetic threshold of the C((3)P) + O2(X(3)Σ(g)(-)) channel with a yield of 5 ± 2% using vacuum ultraviolet laser pump-probe spectroscopy and velocity-map imaging detection of the C((3)PJ) product between 101.5 and 107.2 nanometers. Our results may have implications for nonbiological oxygen production in CO2-heavy atmospheres.
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Affiliation(s)
- Zhou Lu
- Department of Chemistry, University of California, Davis, CA 95616, USA
| | - Yih Chung Chang
- Department of Chemistry, University of California, Davis, CA 95616, USA
| | - Qing-Zhu Yin
- Department of Earth and Planetary Sciences, University of California, Davis, CA 95616, USA
| | - C Y Ng
- Department of Chemistry, University of California, Davis, CA 95616, USA.
| | - William M Jackson
- Department of Chemistry, University of California, Davis, CA 95616, USA.
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Zhang D, Chen BZ, Huang MB, Meng Q, Tian Z. Photodissociation mechanisms of the CO2(2+) dication studied using multi-state multiconfiguration second-order perturbation theory. J Chem Phys 2013; 139:174305. [PMID: 24206296 DOI: 10.1063/1.4827075] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Employing the multi-state multiconfiguration second-order perturbation theory (MS-CASPT2) and complete active space self-consistent field (CASSCF) methods, the geometries, relative energies (T(v)') to the ground state (X(3)Σg(-)), adiabatic excited energies, and photodissociation mechanisms and corresponding kinetic energy releases for the lower-lying 14 electronic states of the CO2 (2+) ion are studied. The T(v)' values are calculated at the experimental geometry of the ground state CO2 molecule using MS-CASPT2 method and highly close to the latest threshold photoelectrons coincidence and time-of-flight photoelectron photoelectron coincidence spectrum observations. The O-loss dissociation potential energy curves (PECs) for these 14 states are drawn using MS-CASPT2 partial optimization method at C(∞v) symmetry with one C-O bond length ranging from 1.05 to 8.0 Å. Those 14 states are confirmed to be correlated to the lowest four dissociation limits [CO(+)(X(2)Σ(+)) + O(+)((4)S(u)), CO(+)(A(2)Π) + O(+)((4)S(u)), CO(+)(X(2)Σ(+)) + O(+)((2)D(u)), and CO(+)(X(2)Σ(+)) + O(+)((2)P(u))] by analyzing Coulomb interaction energies, charges, spin densities, and bond lengths for the geometries at the C-O bond length of 8.0 Å. On the basis of these 14 MS-CASPT2 PECs, several state/state pairs are selected to optimize the minimum energy crossing points (MECPs) at the CASSCF level. And then the CASSCF spin-orbit couplings and CASPT2 state/state energies are calculated at these located MECPs. Based on all of the computational results, the photodissociation mechanisms of CO2(2+) are proposed. The relationships between the present theoretical studies and the previous experiments are discussed.
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Affiliation(s)
- Dongwen Zhang
- School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Yuquan Road 19A, 100049 Beijing, People's Republic of China
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Gharaibeh MA, Clouthier DJ. A laser-induced fluorescence study of the jet-cooled nitrous oxide cation (N2O+). J Chem Phys 2012; 136:044318. [PMID: 22299882 DOI: 10.1063/1.3679744] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Laser-induced fluorescence and wavelength resolved emission spectra of the à (2)Σ(+) - X̃ (2)Π(i) electronic transition of the jet-cooled nitrous oxide cation have been recorded. The ions were produced in a pulsed electric discharge at the exit of a supersonic expansion using a precursor mixture of N(2)O in high pressure argon. Both spin-orbit components of the 0(0) (0) band were studied at high resolution and rotationally analyzed to provide precise molecular constants for the combining states. Emission spectra were obtained by laser excitation of the 0(0) (0), 2(0) (1), 3(0) (1), and 2(0) (2) absorption bands, providing extensive data on the ground state bending, stretching, and combination vibrational levels. These data were fitted to a Renner-Teller model including spin-orbit, anharmonic, and Fermi resonance terms. The observed energy levels and fitted parameters were found to be comparable to those in the literature predicted from an ab initio potential energy surface.
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Affiliation(s)
- Mohammed A Gharaibeh
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, USA
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